■ - パソコンとパソコンをつなぐものですね

―EIGRPを有効にして、さらにMD5認証のオプションを付けてルーティングします。
―R1からネットワーク10.0.0.0/24宛のルートで不等コストロードバランシングを有効にします。
―ルーティングテーブルに10.0.0.0/24宛のルートが二つあることが確認できます。

■R1
R1(config)#int s1/0
R1(config-if)#ip address 192.168.0.1 255.255.255.0
R1(config-if)#clock rate 64000
R1(config-if)#no shut
R1(config-if)#int s1/1
R1(config-if)#ip address 172.16.0.1 255.255.0.0
R1(config-if)#clock rate 64000
R1(config-if)#no shut
R1(config)#router eigrp 100
R1(config-router)#network 192.168.0.0
R1(config-router)#network 172.16.0.0
R1(config-router)#ex
R1(config)#key chain as100
R1(config-keychain)#key 1
R1(config-keychain-key)#key-string cisco
R1(config-keychain-key)#end
R1(config)#int s1/0
R1(config-if)#ip authentication mode eigrp 100 md5
R1(config-if)#ip authentication key-chain eigrp 100 as100
R1(config-if)#int s1/1
R1(config-if)#ip authentication mode eigrp 100 md5
R1(config-if)#ip authentication key-chain eigrp 100 as100
R1(config-if)#end

■R2
R2(config)#int s1/0
R2(config-if)#ip address 192.168.0.2 255.255.255.0
R2(config-if)#no shut
R2(config-if)#int fa0/1
R2(config-if)#ip address 192.168.1.2 255.255.255.0
R2(config-if)#no shut
R2(config-if)#ex
R2(config)#router eigrp 100
R2(config-router)#network 192.168.0.0
R2(config-router)#network 192.168.1.0
R2(config-router)#ex
R2(config)#key chain as100
R2(config-keychain)#key 1
R2(config-keychain-key)#key-string cisco
R2(config-keychain-key)#end
R2(config)#int s1/0
R2(config-if)#ip authentication mode eigrp 100 md5
R2(config-if)#ip authentication key-chain eigrp 100 as100
R2(config-if)#int fa0/1
R2(config-if)#ip authentication mode eigrp 100 md5
R2(config-if)#ip authentication key-chain eigrp 100 as100
R2(config-if)#end

■R3
R3(config)#int fa0/0
R3(config-if)#ip address 192.168.1.3 255.255.255.0
R3(config-if)#no shut
R3(config-if)#int fa0/1
R3(config-if)#ip address 10.0.0.3 255.255.255.0
R3(config-if)#no shut
R3(config-if)#ex
R3(config)#router eigrp 100
R3(config-router)#network 192.168.1.0
R3(config-router)#network 10.0.0.0
R3(config-router)#ex
R3(config)#key chain as100
R3(config-keychain)#key 1
R3(config-keychain-key)#key-string cisco
R3(config-keychain-key)#end
R3(config)#int fa0/0
R3(config-if)#ip authentication mode eigrp 100 md5
R3(config-if)#ip authentication key-chain eigrp 100 as100
R3(config-if)#int fa0/1
R3(config-if)#ip authentication mode eigrp 100 md5
R3(config-if)#ip authentication key-chain eigrp 100 as100
R3(config-if)#end

■R4
R4(config)#int s2/0
R4(config-if)#ip address 172.16.0.4 255.255.0.0
R4(config-if)#no shut
R4(config-if)#int s2/1
R4(config-if)#ip address 172.31.0.4 255.255.0.0
R4(config-if)#clock rate 64000
R4(config-if)#no shut
R4(config-if)#ex
R4(config)#router eigrp 100
R4(config-router)#network 172.16.0.0
R4(config-router)#network 172.31.0.0
R4(config-router)#ex
R4(config)#key chain as100
R4(config-keychain)#key 1
R4(config-keychain-key)#key-string cisco
R4(config-keychain-key)#end
R4(config)#int s2/0
R4(config-if)#ip authentication mode eigrp 100 md5
R4(config-if)#ip authentication key-chain eigrp 100 as100
R4(config-if)#int s2/1
R4(config-if)#ip authentication mode eigrp 100 md5
R4(config-if)#ip authentication key-chain eigrp 100 as100
R4(config-if)#end

■R5
R5(config)#int s2/0
R5(config-if)#ip address 172.31.0.5 255.255.0.0
R5(config-if)#no shut
R5(config-if)#int fa0/1
R5(config-if)#ip address 10.0.0.5 255.255.255.0
R5(config-if)#no shut
R5(config-if)#ex
R5(config)#router eigrp 100
R5(config-router)#network 172.31.0.0
R5(config-router)#network 10.0.0.0
R5(config-router)#ex
R5(config)#key chain as100
R5(config-keychain)#key 1
R5(config-keychain-key)#key-string cisco
R5(config-keychain-key)#end
R5(config)#int s2/0
R5(config-if)#ip authentication mode eigrp 100 md5
R5(config-if)#ip authentication key-chain eigrp 100 as100
R5(config-if)#int fa0/1
R5(config-if)#ip authentication mode eigrp 100 md5
R5(config-if)#ip authentication key-chain eigrp 100 as100
R5(config-if)#end

■R1のルーティングテーブルを確認する
R1#sh ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

C 172.16.0.0/16 is directly connected, Serial1/1
D 172.31.0.0/16 [90/2681856] via 172.16.0.4, 00:11:05, Serial1/1
D 10.0.0.0/8 [90/2174976] via 192.168.0.2, 00:11:05, Serial1/0←この段階では、ひとつの経路しかない
C 192.168.0.0/24 is directly connected, Serial1/0
D 192.168.1.0/24 [90/2172416] via 192.168.0.2, 00:11:05, Serial1/0

■R1のトポロジテーブルを確認する
R1#sh ip eigrp topology
IP-EIGRP Topology Table for AS(100)/ID(192.168.0.1)

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
r - reply Status, s - sia Status

P 10.0.0.0/8, 1 successors, FD is 2174976
via 192.168.0.2 (2174976/30720), Serial1/0←サクセサ
via 172.16.0.4 (2684416/2172416), Serial1/1←フィージブルサクセサ
P 192.168.0.0/24, 1 successors, FD is 2169856
via Connected, Serial1/0
P 192.168.1.0/24, 1 successors, FD is 2172416
via 192.168.0.2 (2172416/28160), Serial1/0
P 172.31.0.0/16, 1 successors, FD is 2681856
via 172.16.0.4 (2681856/2169856), Serial1/1
via 192.168.0.2 (2686976/2174976), Serial1/0
P 172.16.0.0/16, 1 successors, FD is 2169856
via Connected, Serial1/1

■R1で2倍までの不等コストロードバランシングを有効にする
R1(config)#router eigrp 100
R1(config-router)#variance 2
R1(config-router)#end

■R1のルーティングテーブルをクリアする
R1#clear ip route *

Gateway of last resort is not set

C 172.16.0.0/16 is directly connected, Serial1/1
D 172.31.0.0/16 [90/2681856] via 172.16.0.4, 00:00:06, Serial1/1
[90/2686976] via 192.168.0.2, 00:00:06, Serial1/0
D 10.0.0.0/8 [90/2174976] via 192.168.0.2, 00:00:06, Serial1/0←ふたつの経路情報がある
[90/2684416] via 172.16.0.4, 00:00:06, Serial1/1←ふたつの経路情報がある
C 192.168.0.0/24 is directly connected, Serial1/0
D 192.168.1.0/24 [90/2172416] via 192.168.0.2, 00:00:06, Serial1/0

■R1で10.0.0.0宛のルート情報を確認する
R1#sh ip route 10.0.0.0
Routing entry for 10.0.0.0/8
Known via "eigrp 100", distance 90, metric 2174976, type internal
Redistributing via eigrp 100
Last update from 172.16.0.4 on Serial1/1, 00:03:58 ago
Routing Descriptor Blocks:
* 192.168.0.2, from 192.168.0.2, 00:03:58 ago, via Serial1/0
Route metric is 2174976, traffic share count is 120
Total delay is 20200 microseconds, minimum bandwidth is 1544 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 2
172.16.0.4, from 172.16.0.4, 00:03:58 ago, via Serial1/1
Route metric is 2684416, traffic share count is 97
Total delay is 40100 microseconds, minimum bandwidth is 1544 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 2